Z3

Z3

The Z3 was an electromechanical computer designed by Konrad Zuse. It was one of the world's first working programmable, fully automatic computing machines. It was Turing-complete, at least in theory, and by modern standards the Z3 was one of the first machines that could be considered a complete computing machine (although it lacked the conditional branch operation). The Z3 was completed in 1941 in Berlin and was faster and far more reliable than the Z1 and Z2. The Z3 stored its program on an external tape, thus no rewiring was necessary to change programs. Improving on the basic Z2 machine, he built the Z3 in 1941, which was a highly secret project of the German government. Dr. Jenissen, member of the Reich Air Ministry acted as a government supervisor for orders of the ministry to Zuse's company ZUSE Apparatebau. The German Aircraft Research Institute used it to perform statistical analyses of wing flutter. On 12 May 1941 the Z3 was presented to an audience of scientists including the professors Alfred Teichmann and Curt Schmieden of the Deutsche Versuchsanstalt für Luftfahrt ("German Laboratory for Aviation"), in Berlin. Zuse then moved onto the Z4 design which was completed days before the war ended. The original Z3 was destroyed in 1943 during an Allied bombardment of Berlin. A fully functioning replica was built in the 1960s by Zuse's company, Zuse KG, and is on permanent display in the Deutsches Museum.

Supplement: The Z3 was built with 2,000 relays, implementing a 22 bit word length that operated at a clock frequency of about 5–10 Hz. The Z3 floating point was improved over that of the Z1 in that it implemented exception handling. The exceptional values plus infinity, minus infinity and undefined could be generated and passed through operations.